It's a long haul from New York to Hong Kong any day, at 15 to 16 hours. So imagine what it was like being stuck on board a further 18 hours-plus when a black rainstorm two weeks ago forced a Cathay Pacific flight to abort its landing and divert to Zhuhai.

Flight 831, with 256 passengers on board, was left sitting on the tarmac for hours until Cathay was able to send in a new flight crew, with the first crew having reached legal work-hour limits.

"It was unbelievable," one passenger aboard the Boeing 777 told America's NBC News. "We couldn't get off the plane. The crew couldn't get off the plane. All we could do was wait for it to end."

All passengers remained on board as required by mainland immigration and customs regulations, Cathay said yesterday.

According to the local customs district, officials worked continuously to accommodate 16 new crew members, who took a high-speed ferry from Hong Kong. Customs officials set up a temporary workplace at the airport - which does not have a permanent customs office - to process crew members' paperwork before they flew out of Zhuhai in the early afternoon of March 31.

Cathay said the plane took off at 1.08 pm, more than 16 hours after it landed in Zhuhai. The flight arrived in Hong Kong a little over an hour later.

Perhaps surprisingly, passengers remained in fairly good spirits. "Nobody was freaking out," a passenger told NBC News. "Everyone was abnormally calm considering how long we had been sitting there."

The central government said officials provided passengers with drinking water and food.

A spokesman for Cathay apologised and said: "Regrettably, the delay was further extended by flight time limitation requirements of the operating crew. Our crew had tried their best to look after the passengers under the difficult circumstances."

The same night, 250 passengers and 15 crew on board a Dragonair flight from Shanghai to Hong Kong were forced to spend the night on the plane with little food and water after it was diverted to Shenzhen.

Passengers were barred from leaving as the airport's terminals were full of stranded passengers.

Additional reporting by Emily Tsang

This article appeared in the South China Morning Post print edition as 34 hours to HK - with 16 of them stuck in Zhuhai